Weft detector for loom having a weft inserted by nozzle action



Nov. 12, 1968 J. M. GIUTTARI 3,410,316

WEFT DETECTOR FGR LOOM HAVING A WEFT INSERTED BY NOZZLE ACTION Filed March 15, 1967 45 2 XF O p F l G. *4

INVENTOR.

JOSEPH M GIUTTARI flaw, 9 62%,

ATTORNEYS United States Patent Office 3,410,316 WEFT DETECTOR FOR LOOM HAVING A WEFT INSERTED BY NOZZLE ACTION Joseph M. Giuttari, Cumberland, R.I., assignor to Greenhalgh Mills, Inc., a corporation of Rhode Island Filed Mar. 15, 1967, Ser. No. 623,449 4 Claims. (Cl. 139370) ABSTRACT OF THE DISCLOSURE A weft detector positioned between the warp threads and the weft catching means of a loom in which the wefts are inserted by nozzle action and located ahead of a plurality of weft threads so that if any of the plurality of weft threads are present, the detector device will not stop the loom, but where all of the plurality of weft threads are absent, then the detector device will stop the loom.

Background of the invention In the weaving of many yarns including some of the synthetic yarns, if the loom is stopped, a line is made in the fabric which is an imperfection. In a loom where the weft is inserted by a nozzle action, if the weft does not succeed in completing its passage through all of the warp threads and into the weft catching device on every pick, an imperfection is not necessarily formed. However, if there is any quantity of failure of weft threads reaching the edge of the fabric or the catching means, then an imperfection may be indicated and a stopping of the loom is desired. None of the stop motions which are in use at the present time in this type of a loom are known to provide such a detecting mechanism which will permit of occasional threads being imperfectly inserted, while other weft threads are perfectly inserted. For example, a typical stop motion detecting each weft insertion is shown in United States Patent No. 3,260,283.

Summary of the invention A detector is positioned at such a point that it will engage any one of a plurality of weft threads which are inserted, and if any one of the plurality, for instance such as a group of 3 or 4, are properly inserted, then the loom will keep running. However, if the selected group of plurality of threads are all improperly inserted or do not come to a position fully across the fabric and into the Weft catching means, then the device will cause the loom to stop as such will indicate clearly an imperfect fabric. In this way many imperfections from stopping the loom are avoided.

Description of the drawings FIG. 1 is a perspective view illustrating the stop motion device as in a position to permit the loom to continue operation;

FIG. 2 is a perspective view of the device in a position which will cause stopping of the loom;

FIG. 3 is a diagrammatic view illustrating schematically the position of the detector in full and dotted lines in positions to permit the loom to continue operation;

FIG. 4 is a top plan view illustrating the relation of the detector arm in connection with the warp threads and the weft gripping means; and

FIG. 5 is a wiring diagram of the elecric circuits involved.

Description of the preferred embodiments of this invention In illustrating this invention, a portion of a water jet weft insertion loom, more particularly a Prince jet loom,

3,410,316 Patented Nov. 12, 1968 model LW42, is shown and which is described to some extent in the March 1966 issue of "Skinners Record, pages 163 to 166, and in US. Patent 3,297,057. In FIG. l'the fabric in woven condition is designated 10, while the warps 11 and 12 in shedding position are illustrated in the righthand portion of the view. A temple 14 is mounted on a part of the loom frame 15. The weft thread catching means is designated generally 20 and comprises a plurality of threads 21, 22 and 23 which are twisted in a leno fashion to grab or catch the weft 13 as it is shot into the shed by a fluid jet action from the nozzle 24. A cutter, which is usually a wire at a sufficient degree of temperature to cut the weft threads, is designated 25, it being heated generally to somewhere around 800 centigrade in order to sever these weft threads. The twisted cords are led over a pulley 26 and extend as at 27 to some accumulating device. The various severed ends of the wefts are held in the twisted threads 21, 22 and 23. It is desirable that the twisted threads be as close to the edge of the fabric as possible so as to minimize the length of the pick and thereby reduce waste of the Weft threads. Accordingly a weft detector used in this configuration requires a small structure to be used as the weft feeler.

A bracket 30 serves to mount the weft contacting or feeler mechanism designated generally 31 comprising a switch 32 (see FIG. 3) having a wire-like feeler arm 33 which is of a size to permit it to be positioned between the edge of the warp threads at 34 (FIG. 4) and the weft catching means 20 and across: the plane of the woven cloth at the fell and which is at a location so that it is ahead of a plurality of weft threads 35 as seen in FIG. 3 (ahead of four weft threads here being shown) which have not been severed by a cutter. For purposes of illustration a miniature snap switch is shown, although other types of electromechanical transducers such as switches may be used such as rockable mercury, for example. In the illustrated case a feeler is urged by a plunger 36 forced by spring 37 in a direction to cause the feeler 33 to be moved to the right or toward the shed as seen in FIG. 3. The cutter 25 is located forward of these four weft threads 35 and these weft threads are sequentially cut as heat up occurs and the fabric is taken up. Thus normally there would be a plurality of the weft threads 35 which have been inserted and gripped by the means 20 always located in the space between the weft gripping means 20 and the outer edge 34 of the warps. If for any instance a weft thread such as 42 or 43 is not fully inserted or weft thread 43 does not even reach the outer warp thread 34, (see FIG. 4) still, the presence of other weft threads such as 40 or 41 will be in a position to be engaged by the feeler 33 and no stopping actuation will occur. This asumes, of course, that at least one weft insertion out of three or so subsequent to weft 43 is perfect. The absence of a weft thread to the very outer edge is not necessarily an imperfection. However, should a plurality of weft threads in such a group such as four as illustrated in FIG. 3 occur, then something has gone wrong in the insertion of the weft threads and the feeler will then swing to the position shown in FIG. 2 causing the plunger 36 (see FIG. 3) to engage a contact 45 within the switch and cause a stopping of the loom.

It should be understood that miniature snap switches such as 32 are of a type which may be so connected so that the circuit is either normally open or normally closed and in the case of the circuit being normally closed then the arrangement would be such that the energization of the loom would pass through this switch. However, in other instances where the switch would be normally open, then the closing of the contact such as 45 by the contact portion of the plunger 36 will cause energization of some other means which will cause the stopping of the loom. Similar single pole double throw switches are available with other than snap operating mechanisms and are to be considered equivalents of the illustrated type. Further the details of the stop motion actuation form no part of the instant invention since the main consideration is a configuration of feeler that permits location in a small space between the edge of the fabric and the weft gripping threads. This feeler 33 can in turn actuate any suitable means for causing a circuit condition change.

For completeness of disclosure, FIGURE 5 is a schematic diagram, the line voltage being shown between lines 50 and 51 supplying current to a main drive motor 52 which operates the main drive shaft 53 about which there is a brake designated 54. This brake is operated by solenoid 55 and controlled by closure of contacts 56 through switch 57 which normally closes the contacts 58 to maintain the motor operating. A solenoid 59 controlled by switch 36, which may be the switch 32 of the diagram in FIG. 3, serves to repulse the switch 57 causing it to bridge the contacts 56 to cause a brake to engage the drive shaft and at the same time open the motor circuit to stop the motor.

I claim:

1. A weft detector for a loom in which the weft threads are inserted by nozzle action to form a fabric and with the ends of said weft threads being retained adjacent the fabric edge comprising an electric circuit and switch means, a feeler arm coupled to said switch and positioned adjacent the fabric edge and held normally forward of a plurality of weft ends to engage a leading one of said plurality of said ends which hold the fceler arm in one relation and means to bias said feeler arm in a direction to permit said arm to change said relation in the absence of all of the plurality of weft ends so as to actuate said electric circuit and stop the loom.

2. A weft detector as in claim 1 wherein a cutter for the weft is located forward of said feeler arm.

3. A weft detector as in claim 1 wherein said switch is a miniature snap switch.

4. In a shuttleless loom having weft yarns and an array of warp yarns in which sheds are formed, means for injecting successive lengths of weft yarns into the warp shed, weft catching means spaced from one side of the array of the warp yarns for grasping the inserted weft, control circuit means for controlling the operation of the loom, an elongated feeler arm extending across the plane of the array of warps and positioned in the space between the catching means and the array of warps and normally in a position at one side of a plurality of wefts extending across said space, means to bias said feeler arm laterally of its length and laterally of said wefts extending across said space, and means responsive to the movement of said arm in the absence of all of said plurality of wefts to actuate said control circuit means.

References Cited UNITED STATES PATENTS 2,815,773 12/1957 Ingham 139348 3,135,298 6/1964 Marks 139302 3,237,656 3/1966 Haupt 139-370 3,260,283 7/1966 Svaty et a1. 139-370 3,297,057 1/1967 Mizuno et a1. 139302 HENRY S. JAUDON, Primary Examiner. 

